The present invention relates a fuel tank valve assembly and particularly, to a fuel tank valve assembly that is suitable for use with a fuel tank constructed of a polymeric material. More particularly, the present invention relates to a valve assembly having a mount adapted to be welded to the fuel tank to mount the valve assembly in a fixed position in an aperture formed in the fuel tank.
Mounting assemblies are used to mount a venting valve assembly in a top wall of a fuel tank. See, for example, U.S. Pat. No. 4,966,189 to Harris and PCT International Publication No. WO 99/27284 to Foltz, each of which is incorporated herein by reference. Further, U.S. Pat. No. 5,404,907 to Benjey et al. and U.S. Pat. No. 5,130,043 to Hyde both relate to weldable vapor vent valve systems and are also incorporated by reference herein.
According to the present invention, a method of forming a vent apparatus adapted to be coupled to a fuel tank is provided. The method includes the steps of providing a tank mount made of a weldable plastics material and adapted to be welded to an exterior surface of a fuel tank and injecting a non-weldable plastics material into a valve housing mold cavity containing the tank mount to overmold the tank mount with the non-weldable plastics material to produce a valve housing having a venting outlet arranged to communicate with a valve chamber formed in the valve housing and arranged to extend above the tank mount.
In preferred embodiments, the tank mount is ring-shaped and has either an L-shaped, T-shaped, or J-shaped cross section. During the injecting step, non-weldable plastics material surrounds a portion of the ring-shaped tank mount to mechanically couple the non-weldable valve housing to the weldable tank mount so that a portion of the tank mount can be welded to the exterior surface of a fuel tank to support the valve housing in an aperture formed in the fuel tank.
A spring-loaded valve is positioned to move up and down in a valve chamber formed in the valve housing to open and close an aperture formed in a top wall of the valve housing and arranged to provide an opening into the valve housing venting outlet above the tank mount. The tank mount is positioned to cause a top wall of the tank mount to lie in coplanar relation with the top wall of the valve housing.
Additional features of the present invention will become apparent to those skilled in the art upon consideration of the following description of preferred embodiments of the invention exemplifying the best mode of carrying out the invention as presently perceived.